The invention relates to a new and improved electrosurgical knife coated with a non-stick material which is especially adapted to inhibit build-up of charred tissue, and a method of making same.
Electrosurgical knifes or blades currently utilized by surgeons essentially comprise a surgical steel cutting tool, such as a scalpel, and a source of radio-frequency electrical energy for application to the cutting tool. When used in surgery, the surgeon controls the application of radio-frequency electrical energy to the blade to generate heat and cause hemostasis as tissue is cut. In this manner, surgery can be carried out and bleeding minimized.
Although electrosurgical knives have proven effective for controlling bleeding during surgery, one problem which has resulted is that of tissue sticking to the blade to thereby reduce cutting efficiency and ultimately require replacement of the blade. One approach to overcoming this problem has been to coat the blade with some type of non-stick material to which cauterized tissue is less likely to adhere. Of course, such coating material must be suitable for passing electrical current or at least the coating of the material must be arranged to allow passage of current from the blade to the tissue. A sampling of prior art patents which disclose non-stick coatings for electrosurgical knifes include U.S. Pat. Nos. 4,314,559, 4,333,467, 4,161,950 and 4,481,057.
Although coating electrosurgical knife blades with non-stick material has served to improve the efficiency of surgical procedures, coated blades prepared using prior art methods still suffer from sticking problems. This is because in order to ensure electrical conductivity, small, interspersed conductive locations are provided in the coatings, i.e., small openings are allowed to form in the coating thereby exposing the metallic knife blade. In use of the knife, these conductive locations or openings typically become coated with charred tissue soon rendering the knifes nonconductive and thus unusable.
An additional problem with some of the prior art non-stick coating arrangements is the cost of applying the layers of nonstick material to the blades since typically a two layer conductive and nonconductive surface is provided for each blade, which significantly increases the cost of the blades.